Plate valve



Nov. 6; 1928.

S. B. REDFIELD PLATE VALVE Filed June 29. 1926 INVENTOR nawdenflfledjield 1115 AT l' N EY 7 the proper non-flexing steel.

Patented Nov. 6, 19 28. I I I PA NT I SNOWDEN'B. REDFIELD, or EAS'ION, PENNSYLVANIA, ASSIGNORTO mammals COMPANY, OF'J'ERSEY crrY, NEW JERSEY, A CORPORATION or NEW jJERsnY,

PLATE VALVE. V I

This invention relates to valves for air compressors of the type known to the art as plate valves, in which some form of thin-disc or plate'is held between a valve seat and aback stop and which has a lift from its seat of only a small fraction of an inch. It relates more particularly, however, to an improvement in plate valves for small compressors, in the design of which certaln lllllltd: tions have caused the usual amount of breakage of the valve plate and guide. lVlthout going into a detailed history of the plate valve, it can a tly be pointed out here that a plate valve or a small air compressor, of twelve inch stroke or less, must be of small diameter in order to fit the size of-the cylinder, and cut down the clearance.

At the same time the amount of lift'has to be the same as the lift in a large diameter valve, if not more, since only one circular valve port can be used in a small valve. This means that the valve guide plate, which is necessary in order to insure thereturn of the valve plate to its seat must flex COHSIdGIEIlJly in proportion to the small radial length of the arms. This can be insured if the right tempered steel is used. The steel for the valve plate itself, however, must be such that the valve plate will not flex, but will retam its shape under all conditions, inorder to seat on the valve seat properly and ehmmate I breakage.

guiding arms hav been riveted to the valve plate, which in turn could then be formed of rivets have broken and have caused breakage of the valveplate. vention therefore is to eliminate all these difficulties by providing a valve assembly wherein the valve plate and the guide plate can be of different materials and rivets Figure 1 is a cross sectional view of the valve assembly and plate valve, I

Figure 2 is a detailed illustration of the valve disc, and

Figure 3 is a detailed illustration of the But here the The object of my in-' guide alate,-bothlthe latter being in three:di

=mensional perspective. 1

Referring to the drawings the: usual valve assembly is shown in Figure lwithrthevalve seat A,"aniannularvalve discB, valveguide a plate 6 andia washerE,':tli'eiwholebeingheld together by the usual bolt F and the nut G.. The annular valve disc is in the form of a fiat ring adapted to lie over the ports H in the valve seat A. On the outside circumference of the valve disc B are cut notches or, grooves J pre'ferably opposite to each other. The guide plate C is of the usual construction embodying a central hub K adapted to fit upon the bolt F while extending from the hub K are the two arms L. At the extremities of the arms L are formed arcuate extensionsL substantially a semi-circumference in length which are adapted to be super-imposed over the valve disc B. At the ends 0 of the ex tensions L tongues or ears P have been formed, preferably by stamping, on one side therein. The assembly of the 'valveis as follows: 7

The valve disc B is placedover the ports 31-1, the valve guide plate C is then super- Therefore, to meet this difliculty flexible the valve disc. Thesaid stop plateD with the springs R placed in the pockets Q is super-lmposed upon the guide plate C, the

springs R pressing upon the ends 0 ofthe j arcuate extensions L of the valve guide plate and indirectly upon valve disc B. A dowel 9 pin S, shown in the drawings, placed in the valve seat and liolding the washer E, guide plate Cand stop plate D in position can be used tomake the assembly of the valve'easier. In operation the valve disc B is lifted vertically from its seat when the compression in the cylinder is sufficient to overcome the pressure exertedfon the valve by the air in the other side and the coil springs B. At the end of the compression and discharge stroke it is returned to its seat. As a direct result of the tongues P on the spring guide plate C'fitting into the grooves J on the valve disc B, no

movement of the valve disc other than in a vertical plane is possible and the valve always 3 Pockets Q.

returns to the same position relative to the port ar'ea,s0 that What is known in the art asa seat is quickly formed and loss of efliciency throu h the escape of air on account of minute 'irregIi larities on the surface of the valve seat is eliminated.

In this specification, a valve assembledfor ,necessary changes beingma mere alteration of the position of certain parts.

I claim:

' An improvement in plate valves for com-.

pressors comprisinga valve seat, a plate valve in the form of a flat ring adapted to super-impose and to cover the port area on the said valve seat, notches in the edge of said plate valve, a valve guide having a flat upper surface and radial arms having arcuate extensions for normally holding said plate valve against its seat, and ears formed on the extremities of said extensions for forming loose continual engagement with the said notches in the plate valve, a stop plate, pockets in said stop plate, and springs in said pockets bearing upon the extremities of the saidguide plate and indirectly upon the said plate valve. In testimony whereof I have signed this specification. V SNOWVDEN B. REDFIELDL. 

